2,4,6,-Trisubstituted phenols having anesthetic properties

ABSTRACT

Trisubstituted phenol compounds and methods of using the compounds, e.g., for anesthetizing a subject, are disclosed.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional PatentApplication No. 60/830,893, filed Jul. 13, 2006, the contents of whichare incorporated herein by reference.

BACKGROUND OF THE INVENTION

Alkyl phenols have a broad range of medicinal properties ranging fromcentral nervous system (CNS) effects to antioxidant activities. Theeffects of alkyl phenols on the CNS are generally sedative in nature.For example, the dialkylphenol, propofol (2,6-diisopropylphenol) is usedas an anesthetic agent in both humans and animals. This compound alsoserves as a muscle relaxant, anti-epileptic, anti-emetic, anti-spasmoticand as a bronchodilator.

Diisopropylphenol also has uses in the treatment of pathologies relatingto the presence of free oxygen radicals (see, see, e.g., U.S. Pat. No.5,308,874; U.S. Pat. No. 5,461,080; and Aarts et al., 1995, FEBS Let.357(1): 83-5). For example, propofol has been used to inhibitinflammatory responses of the upper respiratory tract due to oxidativestress (see, e.g., Zaloga et al., The Internet Journal of Emergency andIntensive Care Medicine ISSN 1092-4051; Borgeat et al., 1992, AmericanJ. of Gastroent. 87(5): 672-674). Propofol also has been shown to repairneural damage caused by free oxygen radicals in vitro (Sagara et al.,1999, J. Neurochem. 73(6): 2524-30; Jevtovic-Todorovic et al., 2001,Brain Res. 913(2): 185-9) and has been used in vivo to treat head injury(see, e.g., Kelly et al., Journal of Neurosurgery 90: 1042-1052, 1999

Although propofol is considered to be relatively safe, side effects havebeen reported, including dose-dependent hypotension,hypertriglyceridemia and pancreatitis. In addition, high doses ofpropofol can result in “propofol syndrome”, a serious conditioncharacterized by severe metabolic acidosis and circulatory collapse.

SUMMARY OF THE INVENTION

In one aspect, the invention provides a compound represented by theformula (Formula I):

in which R₁, R₂, R₄ and R₅ are each independently C₁-C₄ alkyl or C₁-C₄haloalkyl; R₃ and R₆ are each independently H, C₁-C₄ alkyl or C₁-C₄haloalkyl; and one of X₁ and X₂ is OH and the other is H, and Y isfluoroalkyl; or X₁ and X₂ taken together are ═O, and Y is C₁-C₄haloalkyl;or a pharmaceutically acceptable salt or prodrug thereof.

In certain embodiments, R₁, R₂, R₄ and R₅ are each methyl. In certainembodiments, wherein R₃ and R₆ are each H. In certain embodiments, oneof X₁ and X₂ is OH and the other is H. In certain embodiments, Y ishaloalkyl. In certain embodiments, Y is halomethyl. In certainembodiments, Y is chloromethyl. In certain embodiments, Y istrifluoromethyl. In one embodiment, the compound is2,6-diisopropyl-4-(1′-hydroxy-2′,2′,2′-trifluoroethyl)phenol.

In another aspect, the invention provides a pharmaceutical compositionincluding a compound of Formula I and a pharmaceutically acceptablecarrier.

In another aspect, the invention provides a method for anesthetizing asubject. The method includes administering a pharmaceutically effectiveamount of a compound of Formula I to the subject.

In another aspect, the invention provides a method of treating headachein a subject in need thereof, the method comprising administering atherapeutically effective amount of a pharmaceutical composition of acompound of the invention to the patient.

In another aspect, the invention provides a method of treating seizuresin a subject in need thereof, the method comprising administering atherapeutically effective amount of a pharmaceutical composition of acompound of the invention to the subject.

In another aspect, the invention provides a method for preventingcellular damage from oxygen radicals, the method comprising contacting acell in need of such treatment with an effective amount of a compound ofthe invention under conditions such that cellular damage from oxygenfree radicals is prevented.

In another aspect, the invention provides a method of treating arespiratory disorder in a subject in need thereof, the method comprisingadministering to the subject an effective amount of a compound of theinvention.

Other aspects and embodiments of the invention will be apparent from thedescription, drawings, and claims herein.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a scheme showing a method of preparing compounds according tothe present invention.

FIG. 2 is a graph showing the direct activation of GABA receptors byphenolic compounds.

DETAILED DESCRIPTION OF THE INVENTION I. Compounds

In one aspect, the invention provides 2,4,6-trisubstituted haloalkylphenols useful as anesthetics. Substitution of alkylphenols withfluorine is believed to be advantageous because fluorine can, at leastin some cases, improve chemical and metabolic stability of a compound,and can favorably affect the pharmacokinetics/pharmacodynamics of smallmolecules.

In one aspect, the invention provides a compound represented by theformula (Formula I):

in which R₁, R₂, R₄ and R₅ are each independently C₁-C₄ alkyl or C₁-C₄haloalkyl; R₃ and R₆ are each independently H, C₁-C₄ alkyl or C₁-C₄haloalkyl; and one of X₁ and X₂ is OH and the other is H, and Y isfluoroalkyl; or X₁ and X₂ taken together are ═O, and Y is C₁-C₄haloalkyl;or a pharmaceutically acceptable salt or prodrug thereof.

In certain embodiments, R₁, R₂, R₄ and R₅ are each methyl. In certainembodiments, wherein R₃ and R₆ are each H. In certain embodiments, R₁,R₂, and R₃, taken together with the carbon atom to which each isattached, comprise a total of three or four carbon atoms. In certainembodiments, R₄, R₅, and R₆, taken together with the carbon atom towhich each is attached, comprise a total of three or four carbon atoms.In certain embodiments, one of X₁ and X₂ is OH and the other is H. Incertain embodiments, Y is haloalkyl. In certain embodiments, Y ishalomethyl. In certain embodiments, Y is chloromethyl. In certainembodiments, Y is trifluoromethyl.

In one embodiment, the compound is2,6-diisopropyl-4-(1′-hydroxy-2′,2′,2′-trifluoroethyl)phenol, as shownbelow:

It will be appreciated that the compounds of the present invention(e.g., compounds of Formula I), may contain one or more asymmetriccarbon atoms. As such, compounds of this invention can exist as eitherindividual enantiomers or diastereomers, or as mixtures of twoenantiomers or two or more diastereomers. Accordingly, a compound of thepresent invention will include both racemic mixtures, and alsoindividual respective enantiomers or stereoisomers that aresubstantially free from one or more other possible enantiomers orstereoisomers. The term “substantially free of other enantiomers orstereoisomers” as used herein means less than 25% of other enantiomersor stereoisomers, preferably less than 10% of other enantiomers orstereoisomers, more preferably less than 5% of other enantiomers orstereoisomers and most preferably less than 2% of other enantiomers orstereoisomers, or less than “X” % of other enantiomers or stereoisomers(wherein X is a number between 0 and 100, inclusive), are present.Methods of obtaining or synthesizing an individual enantiomer ordiastereomer for a given compound are well known in the art and may beapplied as practicable to final compounds or to starting material orintermediates. For example, chiral chromatography or crystallization ofa salt formed with an optical active acid or base can be used toseparate many enantiomers.

In another aspect, the invention provides a pharmaceutical compositionincluding a compound of Formula I together with a pharmaceuticallyacceptable carrier.

In another aspect, the invention provides a method for anesthetizing asubject. The method includes the step of administering apharmaceutically effective amount of a compound of Formula I to thesubject.

In another aspect, the invention provides a method for sedating asubject. The method includes the step of administering an effectiveamount of a compound of Formula I to the subject.

In another aspect, the invention provides a method for preventingcellular damage from oxygen radicals. The method includes the step ofcontacting a cell in need of such treatment with an effective amount ofa compound of Formula I under conditions such that cellular damage fromoxygen free radicals is prevented.

In another aspect, the invention provides a method of preparing acompound represented by the formula (Formula I):

in which R₁, R₂, R₄ and R₅ are each independently C₁-C₄ alkyl or C₁-C₄haloalkyl; R₃ and R₆ are each independently H, C₁-C₄ alkyl or C₁-C₄haloalkyl; and one of X₁ and X₂ is OH and the other is H, and Y isfluoroalkyl; or X₁ and X₂ taken together are ═O, and Y is C₁-C₄haloalkyl. The method includes the step of reacting a phenolic compoundof the formula (Formula II):

in which R₁-R₆ are as described above, with aC₂-C₆-hydroxyhaloalkylating agent under conditions such that thecompound of Formula II is prepared.

In certain embodiments, the C₂-C₆-haloalkylating agent istrifluoroacetaldehyde ethyl hemiacetal. In certain embodiments, whereinthe reacting step includes reacting the compound of Formula II with theC₂-C₆-haloalkylating agent in the presence of a base or Lewis acidcatalyst. In certain embodiments, base catalyst is potassium carbonate.In certain embodiments, the Lewis acid catalyst in ZnCl₂ or ZnI₂.

DEFINITIONS

The term “alkyl,” as used herein, refers to the radical of saturatedaliphatic groups, including straight-chain alkyl groups, branched-chainalkyl groups, and cycloalkyl (alicyclic) groups. In preferredembodiments, a straight chain or branched chain alkyl has 30 or fewercarbon atoms in its backbone (e.g., C₁-C₃₀ for straight chain, C₃-C₃₀for branched chain), preferably 20 or fewer, and more preferably 10 orfewer, and still more preferably 6 or fewer. Similarly, preferredcycloalkyls have from 3-10 carbon atoms in their ring structure, andmore preferably have 3, 4, 5, 6 or 7 carbons in the ring structure.

Moreover, the term “alkyl” as used throughout the specification andclaims is intended to include both “unsubstituted alkyls” and“substituted alkyls,” unless otherwise specified. The term “substitutedalkyls” refers to alkyl moieties having substituents replacing ahydrogen on one or more carbons of the hydrocarbon backbone (e.g., oneto 2n+1 substituents, where n is the number of carbons in thehydrocarbon backbone, and more preferably one to three substituents).Such substituents can include, for example, halogen (i.e., F, Cl, Br, orI), hydroxyl, alkoxy, cyano, amino, sulfhydryl, alkylthio, nitro, orazido moieties. It will be understood by those skilled in the art thatthe moieties substituted on the hydrocarbon chain can themselves besubstituted, if appropriate. Cycloalkyls can be further substituted,e.g., with the substituents described above. The term “alkyl” alsoincludes unsaturated aliphatic groups analogous in length and possiblesubstitution to the alkyls described above, but that contain at leastone double or triple bond respectively.

Unless the number of carbons is otherwise specified, “lower alkyl” asused herein means an alkyl group, as defined above, but having from oneto ten carbons, more preferably from one to six, and most preferablyfrom one to four carbon atoms in its backbone structure (if straightchain), or from three to six carbon atoms in its backbone structure (ifbranched chain). Examples of lower alkyl groups include methyl, ethyl,n-propyl, i-propyl, tert-butyl, hexyl, heptyl, octyl and so forth. In apreferred embodiment, the term “lower alkyl” includes a straight chainalkyl having 4 or fewer carbon atoms in its backbone, e.g., C₁-C₄ alkyl.

The term “anesthesia,” as used herein, refers to a loss of sensation orawareness in a subject resulting from pharmacologic depression of nervefunction. The term “anesthetizing” refers to the induction of anesthesiain a subject. In reference to a nerve, the term “anesthetized” meansthat the ability of the nerve to generate or conduct impulses issignificantly impaired, relative to the capacity of the nerve structureto generate or conduct nerve impulses in the absence of exposure to ananesthetic agent.

The term “haloalkyl,” as used herein, refers to an alkyl group havingone or more (preferably 1 to 3) halogen atoms attached to the alkylcarbon chain. In certain embodiments, a haloalkyl group has 1 to 3fluorine atoms or chlorine atoms attached to the alkyl carbon chain. Ina preferred embodiment, a haloalkyl contains at least one fluorine; analkyl or haloalkyl group containing at least one fluorine atom isreferred to herein as a “fluoroalkyl” group. Preferred fluoroalkylgroups include monofluoromethyl, difluoromethyl, trifluoromethyl andperfluoroethyl.

The term “hydroxyhaloalkylating agent,” as used herein, refers to areagent which can be reacted with a phenolic compound to functionalizethe phenol compound with a hydroxyhaloalkyl group through acarbon-carbon bond. A “C₂-C₆-hydroxyhaloalkylating agent” is ahydroxyhaloalkylating agent which reacts with a phenolic compound andresults in the addition of a C₂-C₆-(1-hydroxy)haloalkyl moiety to thephenolic compound. In general, a hydroxyhaloalkylating agent willinclude a reactive moiety and a haloalkyl chain. The reactive moiety canbe, e.g., a hemiacetal, alkyl halides, tosylates, and the like.

The term “prodrug, as used herein, refers to a compound which isadministered to a subject and can be metabolized to provide a compoundof the invention in vivo. For example, a phenolic ester can be cleavedin vivo to release a phenolic compound of the invention.

The term “sedation,” as used herein, refers to the calming of mentalexcitement or abatement of physiological function by administration of adrug. The term “sedating” refers to the induction of sedation.

The term “subject” or “patient,” as used herein, refers to an animal,preferably a mammal, more preferably a dog, cat, monkey, horse, cow,sheep, or pig, and, in certain preferred embodiments, a human.

Examples of preferred compounds of the invention include the following:

2,6-Diisopropyl-4-(2,2,2-trifluoro-1-hydroxy-ethyl)-phenol.

II. Synthesis

The compounds of the invention can be made by a variety of methods, someof which are known in the art. For example, certain compounds of theinvention can be made as described in the Examples herein, in which a2,6-dialkyl phenol is treated with a hemiacetal of a halogenated (e.g.,chloroalkyl or fluoroalkyl) aldehyde, preferably in the presence of acatalytic amount of a base, such as potassium carbonate, or a Lewis acidsuch as boron trifluoride (BF₃), aluminum trichloride, zinc chloride(ZnCl₂), or zinc iodide (ZnI₂). See, e.g., Gong et al., Bull. Chem. Soc.Japan. 74, 377-383 (2001). This reaction is illustrated in FIG. 1 usingtrifluoroacetaldehyde ethyl hemiacetal to produce para substitution of a2,6-disubstituted phenol 11, in which R and R′ are alkyl groups,resulting in product 12. Other haloaldehyde hemiacetals, such asdifluoroacetaldehyde ethyl hemiacetal (or other reactive alkylatingagents) may be employed. Para-substitution of the phenol ring wasgenerally found to be high using potassium carbonate as catalyst.

As also shown in FIG. 1, the resulting 4-hydroxyalkylphenol 12 can beoxidized, e.g., using standard oxidation conditions such Swern oxidationor oxidizing reagents such as pyridinium chlorochromate (PCC) orDess-Martin periodinane, Jones' reagent and the like, to produce the4-(alkylcarbonyl)phenol 13. Compound 13 can be further reacted, ifdesired, to produce a variety of compounds of the invention.

The structures of compounds can be confirmed using standard analyticaltechniques such as mass spectrometry and NMR.

Some of the novel compounds of this invention can be prepared usingsynthetic chemistry techniques well known in the art (see, e.g.,Comprehensive Organic Synthesis, Trost, B. M. and Fleming, I. eds.,Pergamon Press, Oxford).

III. Pharmaceutical Compositions

The invention also provides pharmaceutical compositions. Thepharmaceutical compositions include an effective amount of a compound ofthe invention (e.g., a compound of Formula I) and a pharmaceuticallyacceptable carrier. In certain embodiments, a pharmaceutical compositionof the invention further includes one or more additional anesthetic orsedative agent.

In certain embodiments, these pharmaceutical compositions are suitablefor topical or oral administration to a subject. In other embodiments,as described in detail below, the pharmaceutical compositions of thepresent invention may be specially formulated for administration insolid or liquid form, including those adapted for the following: (1)oral administration, for example, drenches (aqueous or non-aqueoussolutions or suspensions), tablets, boluses, powders, granules, pastes;(2) parenteral administration, for example, by subcutaneous,intramuscular or intravenous injection as, for example, a sterilesolution or suspension; (3) topical application, for example, as acream, ointment or spray applied to the skin; (4) intravaginally orintrarectally, for example, as a pessary, cream or foam; or (5) aerosol,for example, as an aqueous aerosol, liposomal preparation or solidparticles containing the compound.

The phrase “pharmaceutically acceptable” refers to those compounds ofthe invention, compositions containing such compounds, and/or dosageforms which are, within the scope of sound medical judgment, suitablefor use in contact with the tissues of human beings and animals withoutexcessive toxicity, irritation, allergic response, or other problem orcomplication, commensurate with a reasonable benefit/risk ratio.

In certain embodiments, the pharmaceutically acceptable carrier can be aformulation vehicles similar to those used for propofol, e.g.,emulsions, polymeric micelles, cyclodextrins, and the like.

The phrase “pharmaceutically-acceptable carrier” includespharmaceutically-acceptable material, composition or vehicle, such as aliquid or solid filler, diluent, excipient, solvent or encapsulatingmaterial, involved in carrying or transporting the subject chemical fromone organ, or portion of the body, to another organ, or portion of thebody. Each carrier must be “acceptable” in the sense of being compatiblewith the other ingredients of the formulation and not injurious to thepatient. Some examples of materials which can serve aspharmaceutically-acceptable carriers include: (1) sugars, such aslactose, glucose and sucrose; (2) starches, such as corn starch andpotato starch; (3) cellulose, and its derivatives, such as sodiumcarboxymethyl cellulose, ethyl cellulose and cellulose acetate; (4)powdered tragacanth; (5) malt; (6) gelatin; (7) talc; (8) excipients,such as cocoa butter and suppository waxes; (9) oils, such as peanutoil, cottonseed oil, safflower oil, sesame oil, olive oil, corn oil andsoybean oil; (10) glycols, such as propylene glycol; (11) polyols, suchas glycerin, sorbitol, mannitol and polyethylene glycol; (12) esters,such as ethyl oleate and ethyl laurate; (13) agar; (14) bufferingagents, such as magnesium hydroxide and aluminum hydroxide; (15) alginicacid; (16) pyrogen-free water; (17) isotonic saline; (18) Ringer'ssolution; (19) ethyl alcohol; (20) phosphate buffer solutions; and (21)other non-toxic compatible substances employed in pharmaceuticalformulations.

Wetting agents, emulsifiers and lubricants, such as sodium laurylsulfate and magnesium stearate, as well as coloring agents, releaseagents, coating agents, sweetening, flavoring and perfuming agents,preservatives and antioxidants can also be present in the compositions.

Examples of pharmaceutically-acceptable antioxidants include: (1) watersoluble antioxidants, such as ascorbic acid, cysteine hydrochloride,sodium bisulfate, sodium metabisulfite, sodium sulfite and the like; (2)oil-soluble antioxidants, such as ascorbyl palmitate, butylatedhydroxyanisole (BHA), butylated hydroxytoluene (BHT), lecithin, propylgallate, alpha-tocopherol, and the like; and (3) metal chelating agents,such as citric acid, ethylenediamine tetraacetic acid (EDTA), sorbitol,tartaric acid, phosphoric acid, and the like.

Compositions containing a compound(s) of the invention include thosesuitable for oral, nasal, topical (including buccal and sublingual),rectal, vaginal, aerosol and/or parenteral administration. Thecompositions may conveniently be presented in unit dosage form and maybe prepared by any methods well known in the art of pharmacy. The amountof active ingredient which can be combined with a carrier material toproduce a single dosage form will vary depending upon the host beingtreated, the particular mode of administration. The amount of activeingredient which can be combined with a carrier material to produce asingle dosage form will generally be that amount of the compound whichproduces a therapeutic effect. Generally, out of one hundred percent,this amount will range from about 1 percent to about ninety-nine percentof active ingredient, preferably from about 5 percent to about 70percent, most preferably from about 0.5% percent to about 5% percent forparenteral administration.

Methods of preparing these compositions include the step of bringinginto association a compound(s) of the invention with the carrier and,optionally, one or more accessory ingredients. In general, theformulations are prepared by uniformly and intimately bringing intoassociation a compound of the invention with liquid carriers, or finelydivided solid carriers, or both, and then, if necessary, shaping theproduct.

Compositions of the invention suitable for oral administration may be inthe form of capsules, cachets, pills, tablets, lozenges (using aflavored basis, usually sucrose and acacia or tragacanth), powders,granules, or as a solution or a suspension in an aqueous or non-aqueousliquid, or as an oil-in-water or water-in-oil liquid emulsion, or as anelixir or syrup, or as pastilles (using an inert base, such as gelatinand glycerin, or sucrose and acacia) and/or as mouth washes and thelike, each containing a predetermined amount of a compound(s) of theinvention as an active ingredient. A compound may also be administeredas a bolus, electuary or paste.

In solid dosage forms of the invention for oral administration(capsules, tablets, pills, dragees, powders, granules and the like), theactive ingredient is mixed with one or more pharmaceutically-acceptablecarriers, such as sodium citrate or dicalcium phosphate, and/or any ofthe following: (1) fillers or extenders, such as starches, lactose,sucrose, glucose, mannitol, and/or silicic acid; (2) binders, such as,for example, carboxymethylcellulose, alginates, gelatin, polyvinylpyrrolidone, sucrose and/or acacia; (3) humectants, such as glycerol;(4) disintegrating agents, such as agar-agar, calcium carbonate, potatoor tapioca starch, alginic acid, certain silicates, and sodiumcarbonate; (5) solution retarding agents, such as paraffin; (6)absorption accelerators, such as quaternary ammonium compounds; (7)wetting agents, such as, for example, acetyl alcohol and glycerolmonostearate; (8) absorbents, such as kaolin and bentonite clay; (9)lubricants, such a talc, calcium stearate, magnesium stearate, solidpolyethylene glycols, sodium lauryl sulfate, and mixtures thereof; and(10) coloring agents. In the case of capsules, tablets and pills, thepharmaceutical compositions may also comprise buffering agents. Solidcompositions of a similar type may also be employed as fillers in softand hard-filled gelatin capsules using such excipients as lactose ormilk sugars, as well as high molecular weight polyethylene glycols andthe like.

A tablet may be made by compression or molding, optionally with one ormore accessory ingredients. Compressed tablets may be prepared usingbinder (for example, gelatin or hydroxypropylmethyl cellulose),lubricant, inert diluent, preservative, disintegrant (for example,sodium starch glycolate or cross-linked sodium carboxymethyl cellulose),surface-active or dispersing agent. Molded tablets may be made bymolding in a suitable machine a mixture of the powdered activeingredient moistened with an inert liquid diluent.

The tablets, and other solid dosage forms of the pharmaceuticalcompositions of the present invention, such as dragees, capsules, pillsand granules, may optionally be scored or prepared with coatings andshells, such as enteric coatings and other coatings well known in thepharmaceutical-formulating art. They may also be formulated so as toprovide slow or controlled release of the active ingredient thereinusing, for example, hydroxypropylmethyl cellulose in varying proportionsto provide the desired release profile, other polymer matrices,liposomes and/or microspheres. They may be sterilized by, for example,filtration through a bacteria-retaining filter, or by incorporatingsterilizing agents in the form of sterile solid compositions which canbe dissolved in sterile water, or some other sterile injectable mediumimmediately before use. These compositions may also optionally containopacifying agents and may be of a composition that they release theactive ingredient(s) only, or preferentially, in a certain portion ofthe gastrointestinal tract, optionally, in a delayed manner. Examples ofembedding compositions which can be used include polymeric substancesand waxes. The active ingredient can also be in micro-encapsulated form,if appropriate, with one or more of the above-described excipients.

Liquid dosage forms for oral administration of the compound(s) of theinvention include pharmaceutically-acceptable emulsions, microemulsions,solutions, suspensions, syrups and elixirs. In addition to the activeingredient, the liquid dosage forms may contain inert diluents commonlyused in the art, such as, for example, water or other solvents,solubilizing agents and emulsifiers, such as ethyl alcohol, isopropylalcohol, ethyl carbonate, ethyl acetate, benzyl alcohol, benzylbenzoate, propylene glycol, 1,3-butylene glycol, oils (in particular,cottonseed, groundnut, corn, germ, olive, castor and sesame oils),glycerol, tetrahydrofuryl alcohol, polyethylene glycols and fatty acidesters of sorbitan, and mixtures thereof.

In addition to inert diluents, the oral compositions can includeadjuvants such as wetting agents, emulsifying and suspending agents,sweetening, flavoring, coloring, perfuming and preservative agents.

Suspensions, in addition to the active compound(s) of the invention maycontain suspending agents as, for example, ethoxylated isostearylalcohols, polyoxyethylene sorbitol and sorbitan esters, microcrystallinecellulose, aluminum metahydroxide, bentonite, agar-agar and tragacanth,and mixtures thereof.

Pharmaceutical compositions of the invention for rectal or vaginaladministration may be presented as a suppository, which may be preparedby mixing one or more compound(s) of the invention with one or moresuitable nonirritating excipients or carriers comprising, for example,cocoa butter, polyethylene glycol, a suppository wax or a salicylate,and which is solid at room temperature, but liquid at body temperatureand, therefore, will melt in the rectum or vaginal cavity and releasethe active agent.

Compositions of the present invention which are suitable for vaginaladministration also include pessaries, tampons, creams, gels, pastes,foams or spray formulations containing such carriers as are known in theart to be appropriate.

Dosage forms for the topical or transdermal administration of acompound(s) of the invention include powders, sprays, ointments, pastes,creams, lotions, gels, solutions, patches and inhalants. The activecompound(s) of the invention may be mixed under sterile conditions witha pharmaceutically-acceptable carrier, and with any preservatives,buffers, or propellants which may be required.

The ointments, pastes, creams and gels may contain, in addition tocompound(s) of the invention of the present invention, excipients, suchas animal and vegetable fats, oils, waxes, paraffins, starch,tragacanth, cellulose derivatives, polyethylene glycols, silicones,bentonites, silicic acid, talc and zinc oxide, or mixtures thereof.

Powders and sprays can contain, in addition to a compound(s) of theinvention, excipients such as lactose, talc, silicic acid, aluminumhydroxide, calcium silicates and polyamide powder, or mixtures of thesesubstances. Sprays can additionally contain customary propellants, suchas chlorofluorohydrocarbons and volatile unsubstituted hydrocarbons,such as butane and propane.

The compound(s) of the invention can be alternatively administered byaerosol. This is accomplished by preparing an aqueous aerosol, liposomalpreparation or solid particles containing the compound. A nonaqueous(e.g., fluorocarbon propellant) suspension could be used. Sonicnebulizers are preferred because they minimize exposing the agent toshear, which can result in degradation of the compound.

Ordinarily, an aqueous aerosol is made by formulating an aqueoussolution or suspension of the agent together with conventionalpharmaceutically-acceptable carriers and stabilizers. The carriers andstabilizers vary with the requirements of the particular compound, buttypically include nonionic surfactants (Tweens, Pluronics, orpolyethylene glycol), innocuous proteins like serum albumin, sorbitanesters, oleic acid, lecithin, amino acids such as glycine, buffers,salts, sugars or sugar alcohols. Aerosols generally are prepared fromisotonic solutions.

Transdermal patches have the added advantage of providing controlleddelivery of a compound(s) of the invention to the body. Such dosageforms can be made by dissolving or dispersing the agent in the propermedium. Absorption enhancers can also be used to increase the flux ofthe active ingredient across the skin. The rate of such flux can becontrolled by either providing a rate controlling membrane or dispersingthe active ingredient in a polymer matrix or gel.

Ophthalmic formulations, eye ointments, powders, solutions and the like,are also contemplated as being within the scope of the invention.

Pharmaceutical compositions of the invention suitable for parenteraladministration comprise one or more compound(s) of the invention incombination with one or more pharmaceutically-acceptable sterileisotonic aqueous or nonaqueous solutions, dispersions, suspensions oremulsions (including oil-in-water emulsions), polymeric micelles,cyclodextrin complexes, liposomes, protein nanoparticle formulations, orsterile powders which may be reconstituted into sterile injectablesolutions or dispersions just prior to use, which may containantioxidants, buffers, bacteriostats, solutes which render theformulation isotonic with the blood of the intended recipient orsuspending or thickening agents.

Examples of suitable aqueous and nonaqueous carriers which may beemployed in the pharmaceutical compositions of the invention includewater, ethanol, polyols (such as glycerol, propylene glycol,polyethylene glycol, and the like), and suitable mixtures thereof,vegetable oils, such as olive oil, and injectable organic esters, suchas ethyl oleate. Proper fluidity can be maintained, for example, by theuse of coating materials, such as lecithin, by the maintenance of therequired particle size in the case of dispersions, and by the use ofsurfactants.

These compositions may also contain adjuvants such as preservatives,wetting agents, emulsifying agents and dispersing agents. Prevention ofthe action of microorganisms may be ensured by the inclusion of variousantibacterial and antifungal agents, for example, paraben,chlorobutanol, phenol sorbic acid, and the like. It may also bedesirable to include isotonic agents, such as sugars, sodium chloride,and the like into the compositions. In addition, prolonged absorption ofthe injectable pharmaceutical form may be brought about by the inclusionof agents which delay absorption such as aluminum monostearate andgelatin.

In some cases, in order to prolong the effect of a drug, it is desirableto slow the absorption of the drug from subcutaneous or intramuscularinjection. This may be accomplished by the use of a liquid suspension ofcrystalline or amorphous material having poor water solubility. The rateof absorption of the drug then depends upon its rate of dissolutionwhich, in turn, may depend upon crystal size and crystalline form.Alternatively, delayed absorption of a parenterally-administered drugform is accomplished by dissolving or suspending the drug in an oilvehicle.

Injectable depot forms are made by forming microencapsule matrices ofcompound(s) of the invention in biodegradable polymers such aspolylactide-polyglycolide. Depending on the ratio of drug to polymer,and the nature of the particular polymer employed, the rate of drugrelease can be controlled. Examples of other biodegradable polymersinclude poly(orthoesters) and poly(anhydrides). Depot injectableformulations are also prepared by entrapping the drug in liposomes ormicroemulsions which are compatible with body tissue.

When the compound(s) of the invention are administered aspharmaceuticals, to humans and animals, they can be given per se or as apharmaceutical composition containing, for example, 0.1 to 99.5% (morepreferably, 0.5 to 90%) of active ingredient in combination with apharmaceutically-acceptable carrier.

Regardless of the route of administration selected, the compound(s) ofthe invention, which may be used in a suitable hydrated form, and/or thepharmaceutical compositions of the present invention, are formulatedinto pharmaceutically-acceptable dosage forms by conventional methodsknown to those of skill in the art.

IV. Methods of Use

The compounds of the invention can be used in a variety of methods. Thecompounds of the invention can be used, e.g., as antioxidants, musclerelaxants (e.g., as bronchodilators), antispasmotics, inhibitors ofendocannabinoid catabolism, and anti-nauseants. For discussion ofcertain methods in which the novel compounds and compositions of theinvention may be useful, see, e.g., U.S. patent publication2003-0176513, incorporated herein by reference herein.

In one embodiment, the invention provides a method for anesthetizing asubject. The method includes the step of administering apharmaceutically effective amount of a compound of the invention to thesubject. In preferred embodiments, the subject is a mammal, morepreferably a human.

Preferably, subjects treated with compounds of the invention are able toawaken within 10 to 20 minutes after cessation of delivery. Rapidawakening or abrupt withdrawal of compounds may cause increased anxiety,agitation, and resistance to mechanical ventilation (see, e.g., Mirendaand Broyles, 1995, Chest 108: 539-548). These effects can be reduced orprevented by decreasing dosage in small increments (5 μg/kg per minute)during a period of about 5 to 10 minutes.

Propofol and analogs are known to activate GABA receptors (see, e.g.,Trapani et al., J. Med. Chem. 1998, 41, 1846-1854, incorporated hereinby reference). While the relationship between GABA activation andanesthetic activity is not completely clear, it is believed that theability of a compound to directly activate GABA receptors may be relatedto the anesthetic, sedative, and/or anxiolytic activity of the compound.Compounds of the invention can be tested in in vitroelectrophysiological assays to determine the ability of the compound toactivate GABA receptors.

Preferably, compounds according to the invention are used for short-termsedation. However, in one aspect, the compounds are administered forlonger periods over several days, for example, in the case of severerespiratory failure or status epilepticus (see, e.g., Ronan et al.,1995, Crit. Care Med. 23: 286-293; Carrasco et al., 1993, Chest. 103:557-564. Long-term sedation may result in tolerance and may necessitateincreases in doses (see, e.g., Mayer et al., 1993, Anesth Analg. 76:33-39; Carrasco et al., 1993, Chest. 103: 557-564).

When the compounds are used concomitantly with other medications,hypotension and respiratory depression associated with other medicationsmay occur.

For example, opioids may increase the anesthetic or sedative effects ofpropofol (Crippen, 1992, supra; Ved et al., 1996, Anesthesiology 85:4-10). When analgesic and anxiolytic medications are administered topatients who are receiving a sedative, lower doses of each drug may benecessary (see, e.g., Riker et al., 1994, Crit. Care Med. 22: 433-440;Olsson et al., 1989, Heart Lung. 18: 130-138).

In certain preferred embodiments, the pharmaceutically effective amountis an amount sufficient to achieve a sedation level of at least 2 on theRamsay scale, more preferably at least 3 on the Ramsay scale, still morepreferably at least 4 on the Ramsay scale, and yet more preferably atleast 5 on the Ramsay scale.

In another embodiment, the invention provides a method for sedating asubject. The method includes the step of administering apharmaceutically effective amount of a compound of the invention to thesubject. In preferred embodiments, the subject is a mammal, morepreferably a human. In certain preferred embodiments, thepharmaceutically effective amount is an amount sufficient to achieve asedation level of at least 2 on the Ramsay scale, more preferably atleast 3 on the Ramsay scale, still more preferably at least 4 on theRamsay scale, and yet more preferably at least 5 on the Ramsay scale.

Sedatives are commonly used to reduce or eliminate symptoms of agitationand restlessness that accompany anxiety. Anxiety is a sustained state ofapprehension in response to a real or perceived threat and is associatedwith motor tension and increased sympathetic activity (Crippen et al.,1992, Crit. Care Nurs Q. 15: 52-74). Adverse effects of agitationinclude increases in respiratory rate, heart rate, blood pressure,cardiac contractility, afterload, dysrhythmias, and myocardial oxygenconsumption (Crippen, 1992, supra; Harvey, 1996, Am J Crit. Care. 5:7-18). Use of sedation can prevent physical injury, and can be used incritical care to decrease the activity of a patient, for example, todecrease myocardial oxygen consumption.

Short-term sedation (from several hours to 5 days) may be necessary toreduce anxiety and agitated movements that can affect hemodynamicstability. The compounds of the present invention can be used to reduceor eliminate anxiety during painful or uncomfortable procedures, reducerestlessness in the initial hours after surgery, decrease agitation inpatients with neurological disorders or injury; and promote synchronousbreathing in patients receiving mechanical ventilation (Roekaerts etal., 1993, J Cardiothorac Vasc Anesth. 7: 142-147).

When a compound of the invention is used as a sedative, the dose can betitrated to attain the desired level of sedation. Optimal dosage alsomay be determined by assessing the level of sedation of a patient at agive dose. For example, the Ramsay scale can be used, in which asedation level of 1 corresponds to a patient who is anxious, agitatedand/or restless; a sedation level 2 corresponds to a patient who iscooperative, accepting ventilation, oriented, and tranquil; a sedationlevel 3 corresponds to a sleeping patient who exhibits a brisk responseto a light glabeller tap or a loud auditory stimulus; a sedation levelof 4 corresponds to a sleeping patient who only sluggishly responds to alight glabellar tap or loud auditory stimulus, but who does respond to apainful stimulus; and a sedation level of 5 corresponds to a sleepingpatient who does not respond to even a painful stimulus (see, e.g.,Ramsay et al., 1974, BMJ. 2: 656-659). Use of the scale requires hourlyassessment of sedation at levels 3 and 4. Neurological assessment shouldbe performed at least every 24 hours.

Because of the rapid onset of action of alkyl phenols and the rapiddecrease in blood concentrations after cessation of delivery,neurological assessment does not require prolonged cessation ofsedation. For example, the dose can be decreased or stopped to decreasethe level of sedation and the patient's level of consciousness can beevaluated. The amount of sedation used generally will depend on thepatient's condition. During daytime hours, sedation might be kept atlevels 2 to 3 on the Ramsay scale to accommodate a sleep-wake cycle.Greater sedation, for example, levels 4 or 5, might be used at night orduring painful procedures.

In still another embodiment, the invention provides a method forreducing the level of oxygen free radicals in a tissue. The methodincludes the step of contacting a tissue (whether in vivo or in vitro)with an effective amount of a compound of the invention under conditionssuch that the level of oxygen free radicals in the tissue is reduced.

In still another embodiment, the invention provides a method forpreventing cellular damage from oxygen radicals. The method includes thestep of contacting a cell in need of such treatment (whether in vivo orin vitro) with an effective amount of a compound of the invention underconditions such that cellular damage from oxygen free radicals isprevented.

The compounds of the invention can be used as anti-oxidants. Oxidantsare introduced into an organism through the environment (e.g., uponexposure to sunlight), by smoke inhalation and also are generated duringan inflammatory response. When cells are subjected to oxidative stress,cellular functions can be globally affected.

Free radicals produced during oxidative stress can react with proteins,nucleic acids, lipids, and other biological macromolecules producingdamage to cells and tissues. Free radicals are atoms, ions, or moleculesthat contain an unpaired electron (Pryor, 1976, Free Radicals in Biol.1:1). Free radicals are usually unstable and exhibit short half-lives.Elemental oxygen is highly electronegative and readily accepts singleelectron transfers from cytochromes and other reduced cellularcomponents. For example, a portion of the O₂ consumed by cells engagedin aerobic respiration is univalently reduced to superoxide radical (O₂⁻) (Cadenas, 1989, Ann. Rev. Biochem. 58: 79). Sequential univalentreduction of O₂ ⁻ produces hydrogen peroxide (H₂O₂), hydroxyl radical,and water.

Free radicals can originate from many sources, including aerobicrespiration, cytochrome P-450-catalyzed monooxygenation reactions ofdrugs and xenobiotics (e.g., trichloromethyl radicals, CCl₃, formed fromoxidation of carbon tetrachloride), and ionizing radiation. For example,when tissues are exposed to gamma radiation, most of the energydeposited in the cells is absorbed by water and results in scission ofthe oxygen-hydrogen covalent bonds in water, leaving a single electronon hydrogen and one on oxygen creating two radicals: H and OH.

The hydroxyl radical is the most reactive radical known in chemistry. Itreacts with biomolecules and sets off chain reactions and can interactwith the purine or pyrimidine bases of nucleic acids. Radiation-inducedcarcinogenesis may be initiated by free radical damage (Breimer, 1988,Brit. J. Cancer 57: 6). The “oxidative burst” of activated neutrophilsproduces abundant superoxide radicals, which are believed to be anessential factor in producing the cytotoxic effect of activatedneutrophils. Reperfusion of ischemic tissues also produces largeconcentrations of free oxygen radical, typically superoxide (Gutteridgeet al., 1990, Arch. Biochem. Biophys. 283: 223). Moreover, superoxidemay be produced physiologically by endothelial cells for reaction withnitric oxide, a physiological regulator, forming peroxynitrite, whichmay decay and give rise to hydroxyl radical (Marletta, 1989, TrendsBiochem. Sci. 14: 488; Moncada et al., 1989, Biochem. Pharmacol. 38:1709; Saran et al., 1990, Free Rad. Res. Commun. 10: 221; Beckman etal., 1990, Proc. Natl. Acad. Sci. USA 87: 1620). Additional sources offree oxygen radicals derive from “leakage” of electrons from disruptedmitochondrial or endoplasmic reticular electron transport chains,prostaglandin synthesis, oxidation of catecholamines, and plateletactivation.

Oxygen, though essential for aerobic metabolism, can be converted topoisonous metabolites, such as the superoxide anion and hydrogenperoxide, collectively known as reactive oxygen species (ROS). IncreasedROS formation under pathological conditions is believed to causecellular damage through the action of these highly reactive molecules onproteins, lipids, and DNA. During inflammation, ROS are generated byactivated phagocytic leukocytes; for example, during the neutrophil“respiratory burst”, superoxide anion is generated by the membrane-boundNADPH oxidase. ROS are also believed to accumulate when tissues aresubjected to ischemia followed by reperfusion.

Many free radical reactions are highly damaging to cellular components;they crosslink proteins, mutagenize DNA, and peroxidize lipids. Onceformed, free radicals can interact to produce other free radicals andnon-radical oxidants such as singlet oxygen and peroxides. Degradationof some of the products of free radical reactions can also generatepotentially damaging chemical species. For example, malondialdehyde is areaction product of peroxidized lipids that reacts with virtually anyamine-containing molecule. Oxygen free radicals also cause oxidativemodification of proteins (Stadtman, 1992, Science 257: 1220).

A pharmaceutically effective amount of the compounds described hereincan be used prophylactically or in treatment regimens for inhibition ofoxidation in subjects that are at risk for developing a disease relatedto oxidative stress, such as cancer. Further, many neurodegenerativediseases such as Alzheimer's disease, Huntington's disease, Pickdisease, multiple sclerosis, and others are associated with oxidativestress. Additional free radical-associated diseases include, but are notlimited to: ischemic reperfusion injury, inflammatory diseases(discussed further below), systemic lupus erythematosis, myocardialinfarction, stroke, traumatic hemorrhage, spinal cord trauma, cataractformation, uveitis, emphysema, gastric ulcers, oxygen toxicity,neoplasia, undesired cell apoptosis, and radiation sickness (see, e.g.,U.S. Pat. No. 5,827,880).

A pharmaceutically effective amount for anti-oxidant activity may rangefrom about 100 mg to 1 g of the compound.

Initial doses of the compounds of the invention can be determined by avariety of in vitro and in vivo assays. For example, compounds can betested for their ability to quench free oxygen radicals generated byphoto-illumination of riboflavin (see, e.g., Kubow, 1992, Free RadicalBiology and Medicine 12: 63-81; Frankel, 1984; JAOCS 61: 1908-1917; U.S.Pat. No. 6,132,711) or by determining the formation of malondialdehydedegradation products of arachidonic acid after exposure of arachidonicacid to light (see, e.g., U.S. Pat. No. 5,912,179). Electron spinresonance spectroscopy also can be used to verify the formation ofphenoxyl radicals of fluorine-substituted alkyl phenols in the presenceof free radicals.

Cell-based assays also can be used. In one aspect, a compound of theinvention of the invention has antioxidant activity if the compound,when added to a cell culture or assay reaction (a “test reaction”)produces a detectable decrease in the amount of a free radical, such assuperoxide, or a non-radical reactive oxygen species, such as hydrogenperoxide, as compared to a parallel cell culture or assay reaction thatis not treated with the compound (“control reactions”). As used herein,a “detectable decrease” is one which is significantly different from theamount of free radical concentrations observed in control reactionsusing routine statistical tests known in the art and setting p values to<0.05. In one aspect, a detectable decrease is an at least 10% decreasein the amount of a free radical in a test reaction compared to a controlreaction, and preferably, a 20%, 30%, 40%, or 50% or greater, reduction.

Suitable concentrations (i.e., an effective dose) in vivo can bedetermined by various methods, including generating an empiricaldose-response curve, predicting potency and efficacy and through othermethods used in the pharmaceutical sciences. Since oxidative damage isgenerally cumulative, there is no minimum threshold level (or dose) withrespect to efficacy, although minimum doses for producing a detectabletherapeutic or prophylactic effect for particular disease states can beestablished, as described further below.

As discussed above, the inflammatory response that occurs in mammalsinvolves an oxidative component. Thus, the compounds of the invention ofthis invention are useful as anti-inflammatory agents.

In general, the inflammatory response of mammals is dependent on avariety of inflammatory mediators. Many of these mediators, for example,cytokines, TNF-alpha and IL-2, and the eicosanoids, prostacyclins,thromboxanes and leukiotrienes require an oxidation reaction for theirproduction. A pharmacologically effective amount of a compound of theinvention would inhibit production of these inflammatory mediators andcan be administered to subjects where an anti-inflammatory effect isdesired. Some examples of inflammatory disorders which can be treatedusing compounds according to the invention, include, but are not limitedto: arthritis, inflammation caused by respiratory diseases orenvironmental factors, inflammation due to trauma (includingcomplications from surgery), and inflammation caused by disorders of thecentral nervous system.

Examples of respiratory disorders that can be treated with thefluorinated alkyl phenol compounds include, cystic fibrosis, emphysema,HIV-associated lung disease, chronic obstructive pulmonary disease,asthma, bronchiolitis, bronchopulmonary dysplasia, lung cancer,respiratory distress syndrome (ARD), acid aspiration, idiopathicpulmonary fibrosis, immune-complex-mediated lung injury,ischemia-reperfusion injury, mineral dust pneumoconiosis, Silo-Fillersdisease, and others. The preferred method for treatment of thesedisorders is through the administration of compounds of the invention tothe respiratory tract by using an inhalation device.

A pharmaceutically effective amount of compound delivered as an inhalantranges from about 0.1 mg to 10 mg per inhalation, several times daily.An oral dose would range from about 1 mg to 500 mg.

In vitro and/or in vivo assays may be used to optimize compoundsaccording to the invention. For example, a bead embolization model ofpulmonary inflammation can be used in which antigens are coupled toSepharose beads, which are embolized to the lungs of mice via injectioninto their tail veins. The animals preferably are pre-sensitized to thecoupled antigen. The immune system of the mouse then mounts a vigorousimmune response to the antigen-coupled bead. Focal inflammatoryresponses, which can last for several weeks, can be examined byexamining lung tissue for the size of an embolus and for cytokineproduction. Hilar lymph nodes and spleens also can be examined. In oneaspect, the efficacy of a compound of the invention is determined bymonitoring decreases in focal inflammatory responses. Preferably, atherapeutically effective compound is one which decreases a focalinflammatory response as measured by the size of an embolus by at least30% and which decreases the production of inflammatory cytokines by atleast 10%, preferably, at least 20%, at least 30%, at least 40%, and atleast 50%.

Other inflammatory disorders which can be treated include, but are notlimited to, an autoimmune disease, inflammatory bowel disease, Crohn'sdisease, ulcerative colitis, a disease caused by an infection of a gramnegative bacteria, a degenerative joint disease, such as osteoarthritis,rheumatoid arthritis, rheumatoid spondylitis, or gouty arthritis, asthma(including status asthmaticus), endotoxemia, sepsis, or septic shock.

The compounds of this invention also are useful in treatment ofinflammation in the CNS. Inflammation in the CNS can be caused byoxidative stress, viral disease (i.e. meningitis, HIV-1 infection,HIV-II infection), and by traumatic events. Some traumas that can betreated with the compounds described herein include, but are not limitedto, concussions, brain hemorrhage, edema, stroke, spinal cord injury,and hematomas.

The antioxidant properties of the compounds of the invention also can beexploited in regimens for treatment of cancer. Administration ofanti-oxidants during chemotherapy has been found to aid in theinhibition of tumor growth (Chinery et al., 1997, Nature Medicine 3:1233-1241). In addition, many chemotherapeutic agents have a side effectof promoting free radical formation and thus the general anti-oxidantactivities of alkyl phenols are beneficial. In a preferred embodiment,compounds of this invention are particularly useful for treatment ofcancers of the respiratory tract. Pharmaceutically effective amounts ofcompound used in a chemotherapy regime may range from, e.g., about 1 mgto about 500 g of compound delivered daily.

The compounds of the invention also are useful as anti-emetics, whichare anti-nauseants. A pharmaceutically effective dose to inhibit nauseaand vomiting ranges from about 1 mg to about 500 mg.

The compounds of the invention are also useful in the treatment ofseizures such as, epileptic seizures. Pharmaceutically effectiveanti-convulsive dosages range from about 1 mg to about 500 g daily.

In one aspect, compounds of the invention are assayed for their abilityto scavenge oxygen radicals and cause other beneficial effects oncultured cells, which model inflammatory responses. Theanti-inflammatory activity of compounds also may be evaluated in vivo,for example, in animal models (see, e.g., as described in Young et al.,1984, J. Invest. Dermatol., 82: 367-371; U.S. Pat. No. 6,180,796; U.S.Pat. No. 6,177,610; U.S. Pat. No. 6,114,382; and U.S. Pat. No.6,174,901). Animal models for inflammatory bowel disease include theTNBS colitis model described in Neurath et al., 1995, J. of Exp. Med.182: 1281; IL-2 mutant mice (e.g., Ludviksson et al., 1997, J. ofImmunol. 158: 104); IL-10 mutant mice (Berg et al., 1996, J. of Clin.Investigation 98: 1010); TCR transgenic mice (Mombaerts et al., 1993,Cell 75: 274); and SCID mice comprising CD45+ T cells (Powrie et al.,1994, Immunity 1: 553). Rheumatoid arthritis models include the murinepristane-induced arthritis model (Stasluk et al., 1997, Immunol. 90: 81)and the murine collagen-induced arthritis model (Horsfall et al., 1997,J. of Immunol. 159: 5687). Insulin-dependent diabetes (type 1), anautoimmune disease, can be mimicked by NOD mice (Cameron et al., 1997,J. of Immunol. 159: 4686). Lupus can be mimicked by an (NZWXNZB) F.sub.1mouse model (Santiago et al., 1997, J. of Exp. Med. 185: 65) and by aGRD, LPR mouse (FAS mutation) (Bhandoola et al., 1994, Int. Rev. ofImmunol. 11: 231). Multiple sclerosis can be mimicked by mouse models ofexperimental allergic encephalomyelitis (Karrussis et al., 2001, J.Neuroimmunol. 120 (1-2): 1-9. Other animal models are known in the artand are encompassed within the scope of the invention.

In one embodiment, the efficacy of a particular dose or type of compoundis evaluated by monitoring cytokine production in an animal model ofinflammatory disease (e.g., as described above). Splenocytes, lymphnodes and/or intestinal inflammatory cells obtained from treated animalsand control animals (e.g., animals receiving carrier but nofluorine-substituted alkyl phenol) can be contacted with antibodiesspecific for one or more cytokines and reactivity of these cells withinflammatory cytokines can be used to monitor reduction in inflammation.Cells can be analyzed by flow cytometry, by ELISAs, by ELISPOT assays,or by other methods routine in the art. Standard curves can be generatedusing purified cytokines. Data can be analyzed by routine statisticalmethods, e.g., such as the one sample t-test, to determine whether meanvalues significantly differ from zero. Paired t-tests can be used toanalyze differences between group means while analysis of varianceand/or a Dunnett's t-test can used to analyze multiple comparison data.

Preferably, various clinical parameters of disease are also monitored.For example, in mice, clinical evidence of disease includes weight loss,diarrhea, rectal prolapse and histological evidence of intestinalinflammation. Thus, improvement in these parameters would signifyamelioration of disease. To grade intestinal inflammation in animalmodels, tissue is removed, sectioned and examined histologically, forexample, after staining with hematoxylin and eosin. The degree ofcolonic inflammation can be graded semiquantitatively from 0 to 4 in ablinded fashion by a single pathologist using our usual standardizedtechnique: 0=no inflammation; 1=low level inflammation; 2=intermediatelevel inflammation; 3=high level inflammation with wall thickening; and4=transmural infiltration, and loss of goblet cells with wallthickening. Mast cells also can be scanned and counted. Preferably,samples are evaluated blindly.

For mice with collagen-induced arthritis, mice treated with variousdoses/types of compounds and control mice are examined every other dayand their paws scored as follows: 0, normal; 1, Erythema and mildswelling confined to the ankle joint or toes; 2, Erythema and mildswelling extending from the ankle to the midfoot; 3, Erythema and severeswelling extending from the ankle to the metatarsal joints; and 4,Ankylosing deformation with joint swelling. These parameters can becorrelated with the histological changes in the arthritic joints.Treatment success results in a decrease in the arthritis score withimprovement in the histology. For pristane-induced arthritis, joints maybe measured with a micrometer to detect swelling.

Experimental autoimmune encephalomyelitis can be induced in susceptiblemice by repeated injection of appropriate sensitizing myelin antigens.In one aspect, mice treated with varying doses of compounds according tothe invention and control mice are assessed clinically according to thefollowing criteria: absence of disease; tail atony; hind-limb weakness;hind-limb paralysis; hind-limb paralysis and fore-limb paralysis orweakness; and morbidity. For histological analysis, the spinal cords andbrains can be removed and examined histologically (e.g., by fixing thetissues formalin, staining paraffin-embedded sections and examiningthese using a light microscope. Dispersed splenocytes and cells fromother regions can be studied in-vitro as discussed above.

Optimal dosage and modes of administration to subjects in need oftreatment can readily be determined by conventional protocols,identifying therapeutic endpoints and identifying minimal doses androutes of administration which achieve these endpoints with minimaladverse effects. For, example in the case of arthritis, therapeuticendpoints may include increased mobility, decrease joint swelling,decreased pain, a reduction in inflammatory cytokines, and the like.Additionally, synovial fluid may be analyzed for cytokine andinflammatory protein concentrations, and for leukocyte composition andfunction, according to methods known in the art. Synovial biopsies canbe performed to provide tissue for histological analysis according tomethods known in the art.

In the case of inflammatory bowel disease, such as Crohn's disease, atherapeutic endpoint may include a decrease in the number ofexacerbations or an increase in the amount of time between exacerbationsof the disease, or a decrease in diarrhea observed over the treatmentperiod. One particularly useful index for the assessment of Crohn'sdisease is the Crohn's Disease Activity Index, or CDAI (Best et al.,1976, Gastroenterology 70: 439). The CDAI incorporates 8 variablesrelated to the disease activity and has been used in most recent studiesof therapeutic agents in Crohn's disease. It includes the number ofliquid or very soft stools, the severity of abdominal pain or cramping,general well-being, the presence of extraintestinal manifestations ofthe disease, presence or absence of an abdominal mass, use ofantidiarrheal drugs, hematocrit, and body weight. The composite scoreranges from 0 to about 600. Scores below 150 indicate remission andscores above 450 indicate severe illness. A tested, accepted and diseasespecific quality of life questionnaire also may be administered prior toand after treatment to assess therapeutic progress.

The Irvine Inflammatory Bowel Disease Questionnaire is a 32-itemquestionnaire. It evaluates quality of life with respect to bowelfunction (e.g. loose stools and abdominal pain), systemic symptoms(fatigue and altered sleep pattern), social function (work attendanceand the need to cancel social events) and emotional status (angry,depressed, or irritable). The score ranges from 32 to 224, with higherscores indicating a better quality of life. Patients in remissionusually score between 170 and 190. Also, helpful are endoscopic, x-rayand histological assessment of intestinal disease activity. C-reactiveprotein levels and blood cell sedimentation rate may also be monitoredas systemic indicators of inflammation.

In the case of endotoxemia, a decrease in TNF may be monitored, as wellas the patient's clinical presentation (e.g., resolution of fever). Inthe case of asthma, FEV (forced expiratory volume) may be measured aswell as signs and symptoms of exacerbation. In humans, MS diseaseactivity is gauged by monitoring progression and remittence ofneurological signs and symptoms. The most widely used outcomesmeasurement is called The Expanded Disability Status Scale. Cerebralspinal fluid protein composition and cell content analyzed according tomethods known in the art also may be used to monitor disease activity.Moreover, serial MRI studies show new gadolinium-enhanced brain lesions.

In treatments of respiratory diseases, pulmonary function tests can beused to evaluate lung compliance and function. Inflammatory cells can beobtained from bronchiolar lavages and studied for composition andfunction. Periodic chest x-ray or CT scans also can help assess diseaseactivity.

Where compounds are used prophylactically, the absence of the appearanceof symptoms or a reduction in the severity of symptoms (either overtphysical symptoms or measurable biochemical symptoms) may be monitored.It should be obvious to those of skill in the art that the type oftherapeutic endpoint will vary with the inflammatory condition beingtreated and that such endpoints are routinely assayed by those of skillin the art (e.g., physicians and other healthcare workers).

In one embodiment, a therapeutically effective dose of a compound isprovided which is a dose effective to reduce by at least about 15%, atleast about 50%, or at least about 90% of the expression of a markerassociated with disease (e.g., such as pain, lack of mobility, fever,the number of disease episodes, diarrhea, reduction of skin lesions,asthmatic exacerbations, inflammatory cytokines, such as TNF-alpha,TNF-beta, IL-1, IL-6, IL-8, IL-10, IL-13, INF-gamma, and the like).

In yet a further embodiment, the invention provides a method of treatingheadache. The method includes the step administering a therapeuticallyeffective amount of a pharmaceutical composition of the invention to apatient. In one embodiment, the headache is a migraine. In anotherembodiment, the therapeutically effective amount is an amount effectiveto reduce one or more symptoms of: pain, visual disturbance, auditorydisturbance, and nausea.

The term “effective amount” includes an amount effective, at dosages andfor periods of time necessary, to achieve the desired result, e.g.,sufficient to anesthetize the subject, to sedate the subject, or toprevent cellular damage from oxygen radicals. An effective amount ofcompound of the invention may vary according to factors such as thehealth, age, and weight of the subject, and the ability of the compoundto elicit a desired response in the subject. Dosage regimens may beadjusted to provide the optimum therapeutic response. An effectiveamount is also one in which any toxic or detrimental effects (e.g., sideeffects) of the compound are outweighed by the therapeuticallybeneficial effects.

A therapeutically effective amount of a compound of the invention (i.e.,an effective dosage) may range from about 0.1 to 100 mg/kg body weight,preferably about 0.5 to 50 mg/kg body weight, more preferably about 1.0to about 20 mg/kg body weight, and even more preferably about 4 to 18mg/kg, 6 to 16 mg/kg, 8 to 14 mg/kg, or 10 to 12 mg/kg body weight. Theskilled artisan will appreciate that certain factors may influence thedosage required to effectively treat a subject, including but notlimited to the severity of the disease or disorder, previous treatments,the general health and/or age of the subject, and other diseasespresent. Moreover, treatment of a subject with a therapeuticallyeffective amount of a compound of the invention can include a singletreatment or, in certain embodiments, can include a series oftreatments.

EXAMPLE 1

Compound 1 (2,6-diisopropyl-4-(2,2,2-trifluoro-1-hydroxy-ethyl)-phenol)was prepared as follows:

2,6-diisopropyl-phenol (2 ml) was reacted with trifluoroacetaldehydeethyl hemiacetal (2.3 ml) in the presence of potassium carbonate (0.16g); no solvent was used. The reaction mixture was placed in around-bottomed flask and refluxed for approximately 3 hours at 80-100°C. The reaction mixture may be dark green, but will generally become areddish color during the course of the reaction.

Following reaction, the mixture was diluted with ethyl acetate (about20-25 ml) and washed with water. The organic and aqueous phases wereseparated in a separatory funnel; the addition of n-heptane (or amixture of n-heptane/ethyl acetate up to 50/50) can improve theseparation of phases. The organic phase was washed 3-4 times with waterand the solvent was removed by vacuum or under stream of nitrogen gas.As the solvent was removed, the product began to crystallize; a reddishbyproduct was also seen and could be removed by rinsing the product withheptane. Rinsing with heptane can also reduce the presence of propofol.The crystals can be washed until pale yellow or almost colorless.

The product is readily soluble in ethyl acetate and can berecrystallized from ethyl acetate by concentration of an ethyl acetatesolution or by addition of n-heptane to an ethyl acetate solution.

Compound 1 readily crystallizes at room temperature into white crystalsand does not have the strong chemical smell of propofol. Also, thepresence of two alcohol functions suggest that metabolism of Compound 1may occur primarily through conjugation.

EXAMPLE 2

Compound 1 was synthesized as described in Example 1. The compound wastested in an in vitro assay for direct GABA activation. As shown in FIG.2, Compound 1 (MB003) is capable of direct activation of GABA receptors(MB007 is 2-Isopropyl-6-(2,2,2-trifluoro-ethyl)-phenol; MB009 is2-Isopropyl-6-(2,2,2-trifluoro-1-methyl-ethyl)-phenol; GABA isgamma-aminobutyric acid).

Compound 1 was formulated in 16% Cremophor EL solution in water at aconcentration of approximately 15 mg/ml and tested in rats as follows.

Approximately 15 mg/kg of Compound 1 in the suspension were injectedinto the lateral tail vein of two rats (weight 330-340 g). Rat 1 lostits righting reflex for a total of about 3.5 minutes but appeared normalat about 7.5 minutes post-injection. Rat 2 lost its righting reflex fora total of about 2.0 minutes but appeared normal at about 4.75 minutespost-injection (Rat 2 had been agitated prior to injection). Thus, at adose of about 15 mg/kg administered i.v., Compound 1 MB003 gives 2-3 minanesthesia without tremors, agitation or excitement.

These results demonstrate that compound 1 is a potent short-acting i.v.anesthetic.

EXAMPLE 3

Compound 2(2,2,2-trifluoro-1-(4-hydroxy-3,5-diisopropyl-phenyl)-ethanone or2,6-diisopropyl-4-trifluoroacetylphenol) was prepared from Compound 1 byoxidation with Jones' reagent.

When injected into a rat under conditions similar to those of Example 2,(similar dose and route of administration), Compound 2 caused tremorsand shaking upon i.v. injection and did not appear to induce anesthesia.

All patents, patent applications, and published references cited hereinare hereby incorporated by reference in their entirety.

While this invention has been particularly illustrated and describedwith reference to particular examples, it will be understood by thoseskilled in the art that various changes in form and details may be madetherein without departing from the scope and spirit of the inventionencompassed by the appended claims.

1. A compound represented by the formula:

wherein R₁, R₂, R₄ and R₅ are each independently C₁-C₄ alkyl or C₁-C₄haloalkyl; R₃ and R₆ are each independently H, C₁-C₄ alkyl or C₁-C₄haloalkyl; and one of X₁ and X₂ is OH and the other is H, and Y isfluoroalkyl; or X₁ and X₂ taken together are ═O, and Y is C₁-C₄haloalkyl; or a pharmaceutically acceptable salt or prodrug thereof. 2.The compound of claim 1, wherein R₁, R₂, R₄ and R₅ are each methyl. 3.The compound of claim 1, wherein R₃ and R₆ are each H.
 4. The compoundof claim 1, wherein one of X₁ and X₂ is OH and the other is H.
 5. Thecompound of claim 1, wherein Y is haloalkyl.
 6. The compound of claim 5,wherein Y is halomethyl.
 7. The compound of claim 6, wherein Y ischloromethyl.
 8. The compound of claim 1, wherein Y is trifluoromethyl.9. The compound of claim 1, wherein the compound is2,6-diisopropyl-4-(1′-hydroxy-2′,2′,2′-trifluoroethyl)phenol.
 10. Apharmaceutical composition comprising a compound of claim 1 and apharmaceutically acceptable carrier.
 11. A method for anesthetizing asubject, the method comprising administering a pharmaceuticallyeffective amount of a compound of claim 1 to the subject.
 12. A methodof treating headache in a subject in need thereof, the method comprisingadministering a therapeutically effective amount of a pharmaceuticalcomposition of a compound of claim 1 to the patient.
 13. A method oftreating seizures in a subject in need thereof, the method comprisingadministering a therapeutically effective amount of a pharmaceuticalcomposition of a compound of claim 1 to the subject.
 14. A method forpreventing cellular damage from oxygen radicals, the method comprisingcontacting a cell in need of such treatment with an effective amount ofa compound of claim 1 under conditions such that cellular damage fromoxygen free radicals is prevented.
 15. A method of treating arespiratory disorder in a subject in need thereof, the method comprisingadministering to the subject an effective amount of a compound ofclaim
 1. 16. A method of preparing a compound represented by the formula(Formula I):

in which R₁, R₂, R₄ and R₅ are each independently C₁-C₄ alkyl or C₁-C₄haloalkyl; R₃ and R₆ are each independently H, C₁-C₄ alkyl or C₁-C₄haloalkyl; and one of X₁ and X₂ is OH and the other is H, and Y isfluoroalkyl; or X₁ and X₂ taken together are ═O, and Y is C₁-C₄haloalkyl; the method comprising the step of reacting a phenoliccompound of the formula (Formula II):

in which R₁-R₆ are as described above, with aC₂-C₆-hydroxyhaloalkylating agent under conditions such that thecompound of Formula II is prepared.
 17. The method of claim 16, whereinthe C₂-C₆-hydroxyhaloalkylating agent is trifluoroacetaldehyde ethylhemiacetal.